BRUSSELS, Aug 29 (Reuters) - Belgian biomedical group ThromboGenics reported a 37 percent rise in revenue on Thursday on the back of sales of its main drug Jetrea, an eye treatment that was launched in both the United States and Europe this year.

The drugmaker, which entered Belgium's blue-chip Bel-20 stock index in March, said revenues rose to 102.7 million euros ($135.8 million) from 75.1 million euros due to Jetrea's U.S. sales and payments related to sales in Europe by partner Alcon, a unit of Novartis.

Nevertheless Jetrea's U.S. sales undershot market expectations of 15 million euros, according to Jan De Kerpel, analyst at KBC Securities, indicating it would take more time to win over doctors.

"Further medical education is needed to get to the full potential of the product," Jan De Kerpel an analyst from KBC Securities said.

ThromboGenics shares have dropped more than 10 percent in the past two weeks and are some 40 percent lower than their peak in January, on the eve of Jetrea's U.S. launch. The stock will be taken off the European Stoxx600 index in September.

Jetrea is a treatment for vitreomacular adhesion, an ageing-related vision problem that can lead to blindness.

The treatment received EU approval in March and in April it was launched in Britain, Germany and Scandinavia, overall triggering the disbursement of 90 million euro of milestone payments from Alcon, which is selling the drug outside the United States.

The average forecast for turnover this year is 135 million euros, according to a ThomsonReuters I/B/E/S poll, and for net profit of 70 million euros. ($1 = 0.7562 euros) (editing by Philip Blenkinsop)